Alzheimer's disease (AD) is a neurodegenerative disease characterized by deterioration of intellectual and emotional functioning, afflicting 40% of those over 85. Pathological hallmarks of the disease, amyloid beta plaques from A(3 peptide deposition and neurofibrillary tangles from hyperphosphorylated tau, have been shown to evolve in a temporal and spatial manner. Our laboratory is interested in understanding the early mechanisms that cause or perpetuate this temporal and spatial progression of AD pathogenesis. We hypothesize that TNF-a mediated inflammation perpetuates disruption of neuronal Ca2+ homeostasis via the action(s) of neighboring activated microglia in an AD model where genetic predisposition to amyloid and tau pathologies exist and that dampening this inflammatory response will diminish the pathologic effects on Ca2+ signaling and synaptic transmission. We propose: AIM I. Examine the effect of increased TNF-a signaling on Ca2+ homeostasis in vitro. We will utilize pharmacological treatments and real-time calcium imaging to ascertain changes in signaling cascades in a Transwell co-culture system exposed to recombinant TNF-a. In AIM II, we will work to elucidate the molecular mechanism underlying TNF-a-mediated effects on intracellular Ca2+ release. In order to examine the alterations in signaling cascades, we will utilize molecular biology, electrophysiological, mathematical, as well as focal IPS uncaging techniques. Lastly, in AIM III, we will further elucidate the molecular mechanism underlying TNF-a mediated affects on intracellular Ca2+. This will be performed by the addition of specific pharmacological inhibitors and biochemical reagents that will allow us to tease apart the signaling interactions between the two cascades. This work will provide major insight into the involvement of TNF-a mediated inflammation in the temporal and spatial progression of early AD pathogenic events. Alzheimer's disease (AD) is the most prominent neurological disease facing future generations. Current statistics point to AD afflicting more than 4 million Americans and with the aging "Baby Boomer" generation is projected to swell to 10-15 million in the near future. Along with the financial consequences of treating AD, emotional ties to those with AD have led to considerable research to determine the forces that drive initiation and progression of AD. With the intimate knowledge of the genesis of disease processes, future research will undoubtedly focus on inhibiting these pathogenic signaling mechanisms with the ultimate goal to derive novel therapeutics.